Microbial biopesticides for insect pest management in India: Current status and future prospects.

The biopesticide industry in India is undergoing rapid change, reflecting increased global trade in agricultural commodities, a changing regulatory environment and evolving consumer preferences. Currently biopesticides comprise ≈ 5% of the Indian pesticide market, with at least 15 microbial species and 970 microbial formulations registered through the Central Insecticides Board and Registration Committee (CIBRC). As of 2017, over 200 products based on entomopathogenic fungi (Beauveria bassiana, B. brongniartii, Metarhizium anisopliae s.l., Lecanicillium lecanii and Hirsutella thompsonii) and nematicidal fungi (Purpureocillium lilacinum and Pochonia chlamydosporia) are registered for use against various arthropods and plant parasitic nematodes. Regarding bacteria, over 30 products based on Bacillus thuringiensis (Bt) subsp. kurstaki are registered against bollworms, loopers and other lepidopterans, while 12 based on Bt subsp. israelensis and three with Bt subsp. sphaericus have been used against mosquitoes. Two viruses are registered, namely Helicoverpa armigera nucleopolyhedrovirus (22 products) and Spodoptera litura nucleopolyhedrovirus (5 products) for use against bollworms and armyworms. Four entomopathogenic nematode species are sold in Indian market. These include long-lasting wettable powder formulations of Heterorhabditis indica developed by the ICAR-National Bureau of Agricultural Insect Resources, Bengaluru which have been distributed on a large scale to control white grubs and other sugarcane pests. Biopesticide research on the subcontinent is at a relatively early stage, but evolving rapidly, and focusing on indigenous entomopathogens. Despite onerous regulation, quality-control issues and limited large-scale production facilities, investment in domestic fermentation technologies, improved delivery systems, and promotion of biological control through private and public initiative will increase the share of microbial biopesticides in the country.

Computational protein design and protein-ligand interaction studies for the improvement of organophosphorus degrading potential of Deinococcus radiodurans.

The organophosphorus hydrolase enzyme is involved in the catalyzing reaction that involve hydrolysis of organophosphate toxic compounds. An enzyme from Deinococcus radiodurans reported as homologous to phosphotriesterase and show activity against organophosphate. In the past activity of this enzyme is low and efforts made to improve the activity by experimental mutation study. However only very few organophosphates tested against very few catalytic site mutations. In order to improve the catalytic power of the organophosphorus hydrolase enzyme, we carried out systematic functional hotspot based protein engineering strategy. The mutants tested against 46 know organophosphate compounds using molecular docking study. Finally, we carried out an extensive molecular docking study to predict the binding of 46 organophosphate compounds to wild-type protein and mutant organophosphorus hydrolase enzyme. At the end we are able to improve the degrading potential of organophosphorus hydrolase enzyme against organophosphate toxic compounds. This preliminary study and the outcome would be useful guide for the experimental scientist involved in the bioremediation of toxic organophosphate compounds.

Population genetic structure of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) using mitochondrial cytochrome oxidase I (COI) gene sequences from India.

Pink bollworm (PBW), Pectinophora gossypiella is one of the most destructive pest's globally inflicting huge economic losses in cotton even during later stages of crop growth. In the present investigation, the population genetic structure, distribution, and genetic diversity of P. gossypiella in cotton growing zones of India using partial mitochondrial DNA cytochrome oxidase-I (COI) gene was addressed. The overall haplotype (Hd), number of nucleotide differences (K), and nucleotide diversity (π) were 0.3028, 0.327, and 0.00047, respectively which suggest that entire population exhibited low level of genetic diversity. Zone-wise clustering of population revealed that central zone recorded low level of Hd (0.2730) as compared to north (0.3619) and south (0.3028) zones. The most common haplotype (H1) reported in all 19 locations could be proposed as ancestral/original haplotype. This haplotype with one mutational step formed star-like phylogeny connected with 11 other haplotypes. The phylogenetic relationship studies revealed that most haplotypes of populations are closely related to each other. Haplotype 5 was exclusively present in Dharwad (South zone) shared with populations of Hanumangarh and Bathinda (North zone). The result indicated that there is no isolation by distance effect among the Indian populations of PBW. The present study reports a low genetic diversity among PBW populations of India and H1, as ancestral haplotype from which other haplotypes have evolved suggests that the migration and dispersal over long distance and invasiveness are major factors.

Molecular modeling and structural analysis of nAChR variants uncovers the mechanism of resistance to snake toxins.

Nicotinic acetylcholine receptors (nAChRs) are neuromuscular proteins responsible for muscle contraction upon binding with chemical stimulant acetylcholine (ACh). The α-neurotoxins of snake mimic the structure of ACh and attacks nAChRs, which block the flow of ACh and leads to numbness and paralysis. The toxin-binding site of alpha subunit in the nAChRs is highly conserved throughout chordate lineages with few exceptions in resistance organisms. In this study, we have analyzed the sequence and structures of toxin-binding/resistant nAChRs and their interaction stability with toxins through molecular docking and molecular dynamics simulation (MDS). We have reported the potential glycosylation residues within the toxin-binding cleft adding sugar moieties through N-linked glycosylation in resistant organisms. Residue variations at key positions alter the secondary structure of binding cleft, which might interfere with toxin binding and it could be one of the possible explanations for the resistance to snake venoms. Analysis of nAChR-α-neurotoxin complexes has confirmed the key interacting residues. In addition, drastic variation in the binding stability of Mongoose nAChR-α-Bungarotoxin (α-BTX) and human nAChR-α-BTX complexes were found at specific phase of MDS. Our findings suggest that specific mutations in the binding site of toxin are potentially preventing the formation of stable complex of receptor-toxin, which might lead to mechanism of resistance. This in silico study on the binding cleft of nAChR and the findings of interacting residues will assist in designing potential inhibitors as therapeutic targets.

The morphometric analysis of the mental foramen in adult dry human mandibles: a study on the South Indian population.

AIM: The mental foramen is a small foramen which is located in the antero-lateral aspect of the body of the mandible. It is situated midway between the upper and the lower border of the mandible and it transmits the mental nerve and the vessels. The knowledge on the anatomy of the mental foramen is very important in clinical dentistry and in surgical procedures which involve that area. MATERIAL AND METHODS: Our study was conducted on 90 adult dry human mandibles from the south Indian population, irrespective of age and sex. The location, shape, orientation and the presence of the accessory foramen were studied by visual examination. The size and position of the mental foramen were measured by using a digital vernier caliper. The SPSS, version 15 software was used for the statistical analysis, to calculate the minimum, maximum, incidence, mean and standard deviation. RESULTS: In a majority of the mandibles, the mental foramen was located at the level of the root of the 2(nd) premolar, midway between the inferior margin and the alveolar margin of the mandible. Most of the mental foramina were oval in shape. The orientation of the foramen was postero-superior in 83% of the mandibles. The accessory foramens were noted in five mandibles. CONCLUSION: The knowledge on the variations in the position and size of the mental foramen and the presence of the accessory foramen may be of much use to dental surgeons.

QSAR models of cytochrome P450 enzyme 1A2 inhibitors using CoMFA, CoMSIA and HQSAR.

Quantitative structure-activity relationship (QSAR) studies were conducted on an in-house database of cytochrome P450 enzyme 1A2 inhibitors using the comparative molecular field analysis (CoMFA), comparative molecular similarity analysis (CoMSIA) and hologram QSAR (HQSAR) approaches. The database consisted of 36 active molecules featuring varied core structures. The model based on the naphthalene substructure alignment incorporating 19 molecules yielded the best model with a CoMFA cross validation value q(2) of 0.667 and a Pearson correlation coefficient r(2) of 0.976; a CoMSIA q(2) value of 0.616 and r(2) value of 0.985; and a HQSAR q(2) value of 0.652 and r(2) value of 0.917. A second model incorporating 34 molecules aligned using the benzene substructure yielded an acceptable CoMFA model with q(2) value of 0.5 and r(2) value of 0.991. Depending on the core structure of the molecule under consideration, new CYP1A2 inhibitors will be designed based on the results from these models.

Chimeric monoclonal antibody to tumor necrosis factor alpha (infliximab) in psoriasis.

BACKGROUND: Insights into the pathogenesis of psoriasis have provided opportunities to target key steps in the disease process. Tumor necrosis factor-alpha (TNF- alpha) being crucial to the pathogenesis of psoriasis, monoclonal antibodies against this cytokine have proved useful in its treatment. AIM: To study the efficacy of chimeric monoclonal antibody to TNF- alpha (infliximab) in Indian patients with recalcitrant psoriasis vulgaris. MATERIALS AND METHODS: Three patients with recalcitrant psoriasis vulgaris were studied. Baseline haemogram, biochemical parameters, chest radiograph and Mantoux skin test were performed. A loading dose regimen of 5 mg/kg infliximab was administered at weeks 0, 2 and 6. PASI assessment, adverse drug event monitoring and laboratory assessments were carried out at 2-week intervals until week 10. Patients were followed up until week 22 for relapse. RESULTS: Infliximab was well tolerated. The mean PASI was 25.4 at presentation and declined to 5.5 at 10 weeks. PASI 75 was attained at a mean of 9.6 weeks. Relapse occurred at a mean of 18.6 weeks after the first infusion. CONCLUSIONS: This study on Indian patients brings out the importance of cytokine-based therapies in psoriasis. Indigenous production could make these therapies a viable therapeutic option for psoriasis patients in the near future.

Isolation and characterization of a green tissue-specific promoter from pigeonpea [Cajanus cajan (L.) Millsp.].

Expression of rbcS genes encoding small subunit of rubisco, most abundant protein in green tissue, is regulated by at least three parameters--tissue type, light conditions and stage of development. One of the green tissue-specific promoters of rbcS gene family was isolated from pigeonpea by PCR. Expression of uidA gene encoding beta-glucuronidase in the transgenic tobacco plants under the control of pigeonpea rbcS promoter, clearly showed that this promoter was as strong as pea rbcS3A promoter characterized earlier. Study of the sequence similarity with pea rbcS3A promoter, especially the region (boxes I and III) that is required for rbcS3A expression, showed more than 50% divergence. In contrast, pigeonpea promoter sequence isolated in the present study was more similar to that of spinach and rice rbcS promoters.

Autoimmune thyroiditis perdating the presentation of systemic lupus erythematosus: two cases and a review of literature.

Autoimmune diseases are commonly encountered in dermatology practice. While the association of two autoimmune diseases in the same individual is not unknown, it is relatively rare for the second disease to be suspected based on cutaneous manifestations. We present two such cases wherein cutaneous manifestations were the first clue to the development of lupus erythematosus in a setting of autoimmune thyroiditis. Further, we have reviewed literature on this uncommon occurrence and discuss various aspects of this association.

Metabolic flux analysis of Clostridium thermosuccinogenes: effects of pH and culture redox potential.

Clostridium thermosuccinogenes are anaerobic thermophilic bacteria that ferment various carbohydrates to succinate and acetate as major products and formate, lactate, and ethanol as minor products. Metabolic carbon flux analysis was used to evaluate the effect of pH and redox potential on the batch fermentation of C. thermosuccinogenes. In a first study, the effects of four pH values (6.50, 6.75, 7.00, and 7.25) on intracellular carbon flux at a constant redox potential of -275 mV were compared. The flux of carbon toward succinate and formate increased whereas the flux to lactate decreased significantly with a pH increase from 6.50 to 7.25. Both specific growth rate and specific rate of glucose consumption were unaffected by changes in pH. The fraction of carbon flux at the phosphoenolpyruvate (PEP) node flowing to oxaloacetate increased with an increase in pH. At the pyruvate node, the fraction of flux to formate increased with increasing pH. At the acetyl CoA node, the fraction of flux to acetate increased significantly with an increase in pH. A second study elucidated the effect of four controlled culture redox potentials (-225, -250, -275, and -310 mV) on metabolic carbon flux at a constant pH of 7.25. Lower values of culture redox potential were correlated with increased succinate, acetate, and formate fluxes and decreased ethanol and hydrogen fluxes in C. thermosuccinogenes. Lactate formation was not significantly influenced by redox potential. At the PEP node, the fraction of carbon to oxaloacetate increased with a decrease in redox potential. At the pyruvate node, the fraction of carbon to formate increased, while at the acetyl CoA node, the fraction of carbon flux to acetate increased with reduced redox potential. The presence of hydrogen in the headspace or the addition of nicotinic acid to the growth media resulted in increased hydrogen and ethanol fluxes and decreased succinate, acetate, formate, and lactate fluxes.

Elucidation of enzymes in fermentation pathways used by Clostridium thermosuccinogenes growing on inulin.

Based on the presence and absence of enzyme activities, the biochemical pathways for the fermentation of inulin by Clostridium thermosuccinogenes DSM 5809 are proposed. Activities of nine enzymes (lactate dehydrogenase, phosphoenolpyruvate carboxylase, malate dehydrogenase, fumarase, fumarate reductase, phosphotransacetylase, acetate kinase, pyruvate kinase, and alcohol dehydrogenase) were measured at four temperatures (37, 47, 58, and 70 degrees C). Each of the enzymes increased 1.5 to 2.0-fold in activity between 37 and 58 degrees C, but only lactate dehydrogenase, fumarate reductase, malate dehydrogenase, and fumarase increased at a similar rate between 58 and 70 degrees C. No acetate kinase activity was observed at 70 degrees C. Arrhenius energies were calculated for each of these nine enzymes and were in the range of 9.8 to 25.6 kcal/mol. To determine if a relationship existed between product formation and enzyme activity, serum bottle fermentations were completed at the four temperatures. Maximum yields (in moles per mole hexose unit) for succinate (0.23) and acetate (0.79) and for biomass (29.5 g/mol hexose unit) occurred at 58 degrees C, whereas the maximum yields for lactate (0.19) and hydrogen (0.25) and the lowest yields for acetate (0.03) and biomass (19.2 g/mol hexose unit) were observed at 70 degrees C. The ratio of oxidized products to reduced products changed significantly, from 0.52 to 0.65, with an increase in temperature from 58 to 70 degrees C, and there was an unexplained detection of increased reduced products (ethanol, lactate, and hydrogen) with a concomitant decrease in oxidized-product formation at the higher temperature.